1. Field of the Invention
The present invention relates to apparatus for managing livestock, and more particularly, to a dehorner for livestock.
2. Description of Related Art
Certain mammals such as cattle, sheep, goats and antelope have hard protuberances extending from the frontal bone of their skulls. These hard protuberances, generally referred to as horns, consist of a bony core covered with a sheath of keratinous material. Depending on the particular breed, horns are used for varied purposes including defense of self and offspring, domination of others, clearing heavy undergrowth and others too numerous to mention.
Many horned animals such as cattle and sheep are utilized today for the production of foodstuffs such as meat and dairy products. To maximize foodstuff production, such animals are often kept in close quarters with other foodstuff producing animals. When animals are kept in such close quarters, the horn becomes inconsistent with the safe and efficient management of such horned animals for the aforementioned foodstuff production. Dehorning, which is defined as the literal removal of the horns from cattle or other horned livestock, is intended to reduce the possibility of injury to both the horned animals being kept as well as any stockmen or herdsmen managing such animals. When kept in close quarters, any horned animal can severely cut or bruise other animals in the herd. Such injuries reduce the value of the carcass for meat producing animals and reduce the rate of milk production for dairy producing animals. Furthermore, horned animals require more shed and feeding space, thereby reducing the efficiency of such operations. Finally, horned animals are harder and more dangerous to handle during routine management practices such as veterinary care.
There are numerous methods which may be utilized to dehorn livestock. One such technique is generally referred to as chemical dehorning. To chemically dehorn livestock, the hair is clipped or sheared from around the horn button and the surrounding area is ringed with a layer of heavy grease or vaseline. A caustic stick or paste consisting of a caustic potash such as potassium hydroxide or a caustic soda such as sodium hydroxide is then applied over the horn button. The chemical is rubbed over the button until blood appears. After applying the dehorning paste or stick, the animal is kept away from other animals for a few hours and out of the rain for 24 hours. One problem with chemical dehorning is the high risk of weight loss in the animal being dehorned. Typically, two weeks are required for the dehorned animal to regain its original weight. Also, the chemicals used in chemical dehorning may burn the animal's skin or eyes and may als cause scarring. Another disadvantage to chemical dehorning is that the use of chemicals make such techniques best suited for use with small herds which may be kept under constant supervision.
Another dehorning method is generally referred to as the "hot-iron method." Here, a specially designed iron, most often of a bell-shaped design, is utilized to burn the horn off an animal by directly applying a heated iron to the horn for a sufficient period of time. It is generally recommended that the hot-iron method should be used only when the horn button is less than three quarters of an inch in length. Thus, the hot-iron method may not be usable for all dehornings. Furthermore, the hot-iron method typically requires electricity not always available at the location where the animal is to be dehorned.
Another dehorning technique is generally referred to as the "dehorning spoon" or "dehorning tube" method. The dehorning spoon is a small instrument which is used to gouge out the horn buttons of an animal. The dehorning tube, on the other hand, fits over the base of the horn button as well as approximately one-half of an inch of the surrounding skin. The cutting edge of the dehorning tube is pushed and twisted each way until the skin has been cut through. The tube is then turned to about a 45 degree angle and the cutting edge rapidly twisted inward and downward so that the cutting edge of the tube cuts under the area of the horn button and spoons it out. Such techniques are best suited for very young animals having undeveloped horns and may not be recommended for most animals.
Another dehorning technique involves the use of an instrument known as an elastrator. The elastrator stretches a specially made rubber ring and, using the elastrator, the ring is placed down into the hair line of the animal. Smaller horns will drop off in 3 to 6 weeks while larger horns may take 2 months. Too often, however, such time delays are unacceptable.
The most common dehorning techniques involve the use of saw or clippers. To dehorn an animal using a saw or clippers, the animal is confined or unrestrained in a suitable chute, pinchgate, squeeze pen or cattle stock. The horn is then either sawed or clipped off. Various types of clipper dehorners are well known. U.S. Pat. No. 447,611 to Ingraham is directed to a tool for dehorning calves which includes a pointed, V-shaped blade. The handle of the tool is grasped and a blunt instrument struck against the opposite arm of the dehorner to force the cutting blades together, thereby cutting the horn.
Perhaps the most popular dehorner are the two handle clipper dehorners generally known as Barnes-type dehorners. For example, U.S. Pat. Nos. 441,065 to Green, 830,470 to Webster and 1,994,864 to Nisbet all discloses dehorners having a pair of pivoting cutting blades controlled by attached handles. To remove a horn, the horn is placed between the cutting blades and the handles pulled apart until the horn is clipped off. While each of the Green, Webster and Nisbet dehorners includes cutting blades of different shapes, each of disclosed cutting blades is formed having a straight leading edge.
Horned animals typically have horn cells which will produce regrowth of the horn after its removal. To properly dehorn an animal, these cells should also be removed during the dehorning process. However, the cells which produce regrowth of the horn are located around the outer edge of the horn, making their removal more difficult. As a result, it is desired to dig or penetrate the hide before reaching the base of the horn to ensure that the horn, after being removed, will not sprout regrowth. Thus, correct positioning of the dehorner is important to properly dehorn an animal. One problem in using such prior art dehorners having a cutting blade formed with a straight leading edge is the difficulty in properly positioning the cutting blades before removing the horn. Rather than quickly biting into the hide of the animal being dehorned, the cutting blades of such straight leading edge dehorners generally tend to slide when initially grasping the horn, thereby making the precise cutting of the horn difficult. To grasp the horn, a significant amount of pressure must be exerted. Also, by the time the cutting blades begin to firmly grasp the horn, the handles of such dehorner are well separated, thereby making it extremely difficult to adjust the position of the cutting blade after the blade has grasped the horn.
It is an object of this invention to provide a dehorner which quickly bites into the hide of the animal being dehorned, thereby providing a better grasp of the horn upon first contact.
It is another object of this invention to provide a dehorner which reduces the distance or length of dehorner handle separation required to firmly grasp the horn between its blades.
It is a feature of this invention to provide a dehorner having generally U-shaped blades with convexly curved leading edges.
It is another feature of this invention to provide a dehorner having generally U-shaped blades having integrally formed, convexly curved lips.